Material Properties

Every material the penetration engine models, with the constants it actually uses. These are not catalogue figures looked up per run — they are the values compiled into the engine, so a result can be traced back to this table.

18 materials across 5 penetration models

Material Model Density ρ (kg/m³) Compressive σ_c (MPa) Fracture K_IC (MPa√m) Default Thickness (mm) Confinement Factor
Alumina CeramicPONCELET3,8002,5004.00101.5
Aluminum 6061JC2,70027633.006
Ballistic Gel 10%PONCELET1,0604.0n/a1.0
Cinder BlockPONCELET1,8001200.40601.2
Compacted EarthMC1,9006.00.05200
ConcretePONCELET2,4001201.201001.5
Drywall (Gypsum)PONCELET7003.00.10131.0
Dyneema UHMWPEKEVLAR9703,0002.506
Kevlar NIJ IIIKEVLAR1,4403,2003.005
Oak WoodORTHO720850.8040
Packed SandMC1,600100.07150
Pine WoodORTHO500500.5038
PolycarbonateJC1,200380n/a121.0
Red BrickPONCELET1,800600.40901.5
Steel A36JC7,85025065.006
Steel AR500JC7,8601,300100.0010
Tempered GlassPONCELET2,5004000.9061.2
WaterPONCELET1,0000.1n/a1.0

Fracture toughness drives the crack-propagation and spall path, and the engine gates that path on brittle solids — Alumina Ceramic, Cinder Block, Concrete, Red Brick, Tempered Glass. For every other material the stored value is never read; where it is a placeholder rather than a published figure it is shown as n/a. A dash means the property does not apply: confinement is a brittle-only multiplier, and gel and water are scored by depth rather than against a barrier.

How the engine uses these properties →

What do these numbers do? Compressive strength sets the resistance term, density the inertial one, and fracture toughness decides whether a brittle target cracks outward. The penetration calculator runs any load against any of them.